The Senate Subcommittee on Immigration will hold a hearing Thursday on "The Impact of High-Skilled Immigration on U.S. Workers." Its first witness will be an IT worker who trained his visa-holding replacement.

Leo Perrero, an IT worker at Disney until he was laid off in January 2015 -- along with 200 to 300 co-workers -- is one of six scheduled to testify.

This is not the first time lawmakers will hear this story.

Patricia Fluno, a computer programmer in Orlando, testified before Congress in 2003 about losing her job to a foreign worker.

"We lost our jobs and we had to train our replacements so there would be little interruption to Siemens," said Fluno, in her testimony.

"This was the most humiliating experience of my life," said Fluno.

The visa-holding "replacements are sitting at our old desks, answering our old phones, and working on the same systems and programs we did, but for one-third the cost. This is what a manager at Siemens told me," said Fluno. The IT workers received an average salary of $75,000 each.

Others to appear before the congressional panel include John Miano, an attorney who has represented the Washington Alliance Technology Workers in litigation aimed at the H-1B program. Other visa program critics to testify are Hal Salzman, a professor at Rutgers University, and Ron Hira, an associate professor at Howard University.

Chad Sparber, an associate professor of economics at Colgate University, supports the H-1B program and will testify. Also scheduled to appear is Mark O'Neill, the CTO of JackThreads, a retailer.

The immigration subcommittee is chaired by Sen. Jeff Sessions (R-Ala.), a leading critic of the H-1B program. Other members include presidential candidate Sen. Ted Cruz (R-Texas), who has changed his position from supporting an H-1B cap increase, to seeking restrictions on the program and higher salaries for visa holders.

Among the Democratic members is Sen. Richard Blumenthal (D-Conn.), who is seeking an investigation into Northeast Utilities (now Eversource Energy), after a layoff there. The Department of Justice has looked into the utility's layoffs, ending its investigation without filing any charges.